Plaster base



Aug. l, 1939.

J. REID v PLASTER BASE Filed Aug. 20, 1937 2 Sheets-Sheet 2 Patented Aug. 1, 1939 ritme PATENT OFFICE PLASTER BASE James Reid, New York, N. Y.

Application August 20,

19 Claims.

This invention relates to an improved plaster base for use in lieu of the usual wood or metal laths for supporting plaster walls and ceilings of buildings, and more particularly to an improved corrugated fiber board having special facilities for keying the plaster material While plastic in the corrugations thereof.

The use of corrugated fiber board as a base or support for plaster wall and ceiling construction is quite. well known.Y However the present invention provides improved features by which the plastic material when applied to thecorrugated board base may be more securely locked or keyed thereto without the necessity of additional tying means and whereby the successive sections of the base may be so joined as to obviate the likelihood of crackingV of the plaster at the joints ne thereof.

Furthermore the corrugated board material is so treated as to increase its vstrength and durability and its resistance to deteriorating effect of moisture while permitting absorption of moisture from the contacting plaster to facilitate rapid setting thereof.

The object of the inventionA is to provide a plaster base which may not only be economically manufactured but which can be readily and quickly applied and to which plastic material may be securely keyed with minimum loss thereof and which will be strong, light in weight, and of rigid character.

A further object of theinvention is to provide an improved joint between adjacent sections of plaster base board and to insure a plaster deposit of increased thickness coincident with the joint securely interlocked with the base materials tov set, but which will not be materially affectedorweakened by absorption of moisture and which will retain its rigidity.

A further object of the invention is to provide a plaster base having a moisture absorbent surface with which the plaster will unite by entering into the pores or bers of the material and become coalescent throughout, thereby resisting 1937, Serial No. 160,133

separation and possessing a sound deadening characteristic.

A further object of the invention is to provide an improved material for plaster base purposes comprising superposed coextensive strata of mois- 5 ture absorbent and moisture resistant materials whereby capillary attraction of moisture will be exerted, but penetration of the moisture therethrough will be resisted.

A further object of the invention is to control 10 and confine the absorption of moisture to the surface strata of the material to equalize the moisture distribution and prevent warping.

A further object of the invention is to provide a corrugated plaster base which may be solidly packaged for shipping and storage.

With the above primary and other incidental objects in View as will more fully appear inthe specification, the invention consists of thefeatures of construction, the parts and combinations thereof and the mode of operation or their equivalents, as hereinafter described and set forth in the claims.

Referring to the accompanying drawings wherein is shown the preferred, but obviously not necessarily the only form of embodiment of the invention, A v

Fig. 1 is a perspective view of portions of adjacent plaster base sections embodying the present invention. 30

Fig. 2 is anenlarged transverse sectional View thereof. .Y

Fig. 3 is a front elevation of a portion of the Wall employing the corrugated plaster base formingthe subject matter hereof. l v 35 Fig. 4 is a top plan or transverse sectional View .corresponding to Fig. 3. y

Fig'. 5 is an enlarged detail perspective View.

' Fig. 6 is a front elevation of a portion of the plaster base board containing a key opening to receive plaster.

Fig. 7 is a transverse sectional view on line 1 1 of Fig.` 6.

Like parts are indicated by similar characters C of reference throughout the several views. 45

The plaster base or board forming the subject matter hereof comprises an assembly of superf posed alternating corrugated ber sheets and flat liner ber sheets fixedly attached to the corrugated sheets coincident with the crowns of the corrugations. Such assembly when attached to wall studding or overhead joists or other supporting structure, is adapted to receive an adherent coat of plaster, stucco or cement, which will be securely interlocked therewith as hereafter deb scribed. There are thus formed couplets or strata, each consisting of a corrugated sheet and liner sheet, which strata are united one to another in superposed relation.

For illustrative purposes, but with no intent to unduly limit the invention the board or plaster base has been shown as consisting of four such sheets comprising two pairs or strata. The plaster receiving face of the assembly consists of a corrugated sheet I. The back of the board comprises a flat liner sheet 2. Between the back and face may be interposed any number of other corrugated sheets Ia, and flat liner sheets 2a, in alternating relation. The several strata of Whatever number are xedly united into an integral assembly.

The corrugated sheets I and Ia include multiple superposed plies preferably, although not necessarily, of moisture absorbent paper or straw `board, which are united by an interposed stratum 3 of waterproof cement coextensive with the corrugated sheet. While various substances may be used to unite the sheets and interiorly seal them against penetration of moisture without however destroying the'absorbent character of the surface thereof a pitch emulsion or cement having a vegetable pitch base or one of phenolic condensation character or synthetic resinous materials is desirable.

The preferred material is one which will soften or become somewhat plastic under heat and pressure thereby enabling the superposed plies of moisture absorbent material comprising the sheet to be relatively adjusted during the corrugating or sheet forming operation, and which will thereafter harden or set upon cooling. Such intermediate stratum of pitch or other waterproof cement effectively prevents the moisture penetrating entirely through the mass or body of material, but does not prevent nor restrict the capillary attraction of moisture by the surface plies or strata of the sheet.

`The interposed stratum 3 of whatever material is impervious to moisture, and is of such character that it will not be softened or weakened thereby. 'I'herefore the board will retain its strength and rigidity, while the moisture is absorbed by the surface of the material from the immediately contacting portion of the body of plaster to increase the rapidity and uniformity with which the plaster sets.

The corrugated board assembly is formed with marginal rabbets 4 and 5 of different width for overlapping engagement with marginal rabbets of adjacent like sections of the plaster base assembly- The rabbet 4 is formed in the forward side of the board by removing or omitting from the assembly a marginal portion of the overlying strata or couplet comprising the facing sheet I, and intermediate liner sheet 2a, leaving extended beyond the edge thereof the flat backing sheet 2, and the interposed corrugated sheet Ia as shown particularly at the right of Figs. 1 and 2. The rabbet 5 at the opposite margin of the board is formed in the rear side ofthe assembly by removing or omitting from the assembly a marginal portion of the backing sheet 2 and intermediate corrugated sheet la, comprising one couplet, leaving projecting therebeyond the intermediate liner sheet 2a and the corrugated facing sheet I, comprising theV other couplet. The rabbets 4 and 5 are of different width so that the overlap of the narrower rabbet 5 of one section upon the wider rabbet 4 of the adjacent parts of the plaster base assembly together.

they will register with the studding 1 l of the buildingv construction to which the assembly may be nailed within the spaced channels.

The open corrugations of the facing sheet I,

. and other underlying corrugated sheet or sheets,

in event a base of greater thickness is employed, communicate with the channels 6 at the opposite margins thereof. Upon application of plaster 8 in plastic condition to the corrugated face of the assembly the channels 6 are filled flush with the portion of the deposit overlying the corrugated surfaces at opposite sides of the channels, thereby affording within the channels deposits of increased depth. Under pressure of application the plastic material within the channelsk iiows laterally into the open ends ofthe communicating channels afforded by the. c orrugation of the sheets I and Ia, forming interlocking spurs or projections which, when hardened within the open ends of the. corrugation, aiord a very effective and secure keying of the plaster to the base. To effect further interlocking attachment of the plaster deposit, thecorrugated board base is provided with openings Il) at spaced intervals between the spaced vchannels 6 through which the vdepositof plaster 8 is projected. The openings I IJ are of such size as to traverse several of the corrugations, the open ends, of which communicate with the openings. The margins of the openings I0 are beveled or inclined on the forward face of the base assem- L bly, thus providing a converging shape intowhich the plastic material is crowded under pressure during its application to the face of the board. D ue to such inclination of the margins of the openings the' channel ends of certain of the corrugations will be somewhat exposed and will better intercept and receive the plastic material as it is being forced into the opening. Portions of such plastic material are forced laterally beyond the margins of the opening into the open ends of the corrugations where as they harden they form interlocking spurs or projections similar to those contiguous to the channels 6 which serve to further .secure or key the plaster stratum to the supporting board, and tie the component The entrance of the material into the channels of the corrugations is greatly facilitated by the inclination or beveling of the opening margins which v by partially opening the channels tends to deflect the material in greater quantity and to greater depth within the lateral spaces. In addition to the extrusion of the plaster material laterally into interlocking engagement within the corrugations, portions of the material are forced entirely through the openings II) where they expand laterally into overlapping relation with the rear side of the board andwhen hardened form an enlarged head I I which further keys the plaster to its support. Y

The material of the several sheets being ordinarily of moisture absorbent character attracts moisture rapidly from the contacting portions of the plaster deposit, thus causing the plaster to set quickly. However the absorbed moisture does not penetrate through the sheets which include one or more. strata 3 of waterproof material. YIn lieu of a strata of waterproof cement, an intermediate ply of moisture proof paper or other sheet material may be' incorporated in the several sheets forming the board.k The liner sheets 2 and 2a likewise are preferably composed of superposed plies of absorbent material with one or more interposed strata of waterproof cement or plies of moisture resistant material. Such composite sheets'when used for liner sheets or corrugated sheets, or for both, will afford the requisite strength and rigidity and will enable sucient plies of moisture absorbent material to be used to facilitate quick setting of the plaster.

The overlapped joints afford a secure and rigid assembly of successive sections, while the deposit of plaster of increased thickness in the channels affords greater strength at the Vjoints and minimizes cracking of the plaster. n

The interlccked keying effect of the extruded portions of plaster within the corrugations contiguous to the transverse channels and to the holes lil affords a strong, Well interlocked attachment of the plaster deposit to the base which, supplemental to the adhesion of the plaster to the absorbent surfaces, will long resist separation.

IThe incorporation of the waterproofing material between the superposed plies of the material prevents uneven absorption of water by conning the absorbed moisture to the surface plies of the material and restraining it from going entirely through the sheets.

By cutting or crushing the corrugations of the board the assembly may be bent in` either direction into right angle formation to t corners, and likewise may be folded upon itself to parallelism to afford a solid compact formation to facilitate shipping and storage.

After the plaster deposit has become dried and set it is not likely to absorb moisture in large amount, but the deteriorating effect of moisture upon the plaster is due to that absorbed by the supporting base, whether of corrugated board, wood lath, or other material which is subject to expansion and contraction under varying moisture conditions and consequent cracking and breakage of the plaster. While not essential, the back of the present assembled board or base is preferably waterproofed or coatedwith moisture resistant material, such as that hereinbeforedescribed. In dry climates such treatment may not be needed, but for installation in localities having heavy rain fall, or for use under moist air conditions, such waterproof treatment of the back of the material -is quite desirable.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but whichobviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute, the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein `disclosed comprise the preferred form of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within lthe legitimate and valid scope of the appended claims.

Having thus described my invention, I claim:

1. A corrugated plaster base assembly, including superposed adherent portions, an exposed corrugated face on one portion to receive an application of plastic plaster material, spaced channels in the corrugated face of the assembly extending transversely of the corrugations thereof with the opposite margins of which open ends of the corrugations communicate and across which an underlying portion extends to afford a bottomfor the said'channels, theA plaster when applied being adapted to enter said channels and extend thence into the open ends of the corrugations to afford a keying effect.

2.. A corrugated plaster base includingv relatively spaced sections of corrugated material, a supporting back for the relatively spaced corrugated sections extending across the intervening spaces between the corrugated sections, the ends of the corrugations being open contiguous to said spaces to receive plastic material applied to the corrugated sections and within the intervening spaces from which the plastic material flows into the open ends of the corrugations to afford a keying effect.y

3. A corrugated board plaster base including superposed strata,- each including a corrugated sheet and a flat liner sheet attached to the crowns of the corrugations, the superposed strata being laterally offset in overlapping relation whereby the respective strata will each extend beyond the lateral margin of the other strata, but to different degree, one in e-ach direction for overlapping engagement with the extended strata o1' adjacent like boards, whereb-y an extended str-ata of lesser degree will overlap an extended strata ofgreater degree of the neighboring board and vice versa, affording a space between succeeding boards with which the open ends of the corrugations of the adjacent boards communicate and into which plastic plaster material applied to the board may enter from said space to afford a keying eifect.

4. For use in a plaster base assembly, a composite sheet comprising superposed parallel plies of moisture absorbent material, and in interposed stratum of waterproof material forming a continuous union of the superposed plies face to face throughout their extent and adapted to prevent penetration of moisture through the sheet while permitting unrestrained capillary attraction of moisture by the said accompanying plies of absorbent material. f

5. A corrugated plaster base comprising an assembly of alternating interconnected corrugated and flat liner sheets, at least a portion of which comprise superposed adherent parallel plies of moisture absorbent material conforming one to the other throughout and an interposed continuous stratum of moisture resistant cementitious material exposed to the application of moist plaster material from which moisture is absorbed, said moisture resistant material limiting the depth of penetration of the absorbed moisture.`

6. A plaster base including a series of corrugated board sections arranged edge to edge in a common plane, projecting portions forming overlapping joints connecting the sections in series, and open channels intermediate the corrugated portions of succeeding boards and coincident with the overlapping joints thereof With which channels the open ends of the corrugations communicate to receive therein portions of plastic plaster material deposited nels. v

7. A plaster receiving board including superposed'alternating corrugated and plain sheets of material suitably united into an integral board, said board having therein spaced holes transversely intersecting a group of multiple corrugations, with which the open ends of a plurality of corrugations of adjacent portions of the board communicate to receive therein portions of plastic plaster deposited on the board and within the holes to aiord a keying effect.A

8L Aplaster receiving board including superposed alternating corrugated and plain sheets of material suitably united into an integral board, said board having therein spaced holes transin said chanversely intersecting Va group of multiple corrugations,the margins of the holes being beveled to expose multiple channel-like terminals of the corrugations of adjacentportions of the` board which communicate with the holes to receive therein portions of plastic material deposited upon the face of the board and within said holes to aiord a keying efect.

`9. A plaster base comprising a succession of plaster receiving boards having overlapping margins of reduced thickness, the reduced area of onev board being of greater width than the overlapping area of the adjacent board, spaced channels coincident with the joints between succeeding boar-ds aiorded by the difference in the extent of such areas thereof of reduced thickness and llateral openings in the respective boards communicating with said channels to receive portions of plastic plaster material deposited upon the boards and in said channels to afford a keying eiect.

10. As a plaster base, a corrugated board including suitably interconnected corrugated and flat sheets superposed one on the other and interconnected coincident with the crowns of the corrugations, the corrugated sheets comprising multiple parallel plies of moisture absorbent material conforming throughout one to the other and an interposed stratum of waterproof cement interposed vbetween the plies thereof and adherently uniting said plies over an area substantially coextensive with such corrugated sheets.

11. As a` plaster base, a corrugated board assembly including ilat liner sheets and corrugated sheets attached thereto, the plaster contacting face of said corrugated sheets being of absorbent character and an impervious waterproof backing therefor substantially coextensive with the sheet whereby moisture may be absorbed from the contacting Yplaster but such moisture will not penetrate the sheet. Y

12.'As a plaster assembly, a corrugated board assembly including superposed corrugated and flat sheets interconnected coincident with the crowns of the corrugations, said corrugated sheets being of absorbent material and a moisture impervious stra-tum coextensive with the corrugated sheets associated therewith whereby moisture absorbed from contacting plaster may not penetrate the sheets.

13. As a plaster assembly, a corrugated board assembly including superposed corrugated and flat sheets interconnected coincident with the crowns of the corrugations, said corrugated board assembly having spaced plaster receiving keying holes therein extending transversely of multiple corrugations the margins of which are flaring and intersected by the corrugations within which plaster may enter from such opening to aiord a keying eiect.

14. A corrugated plaster board assembly, including superposed multi-ply strata each including corrugated sheets and flat liner sheets united one to the other, the superposed strata being laterally oiset relative to each other whereby the lateral multi-ply margin of each strata will project in overlapping relation beyond the other in reverse directions for overlapping engagement with similar projecting multi-ply margins of neighboring board assemblies.

15. A corrugated plaster base assembly including superposed multi-ply strata each comprising corrugated sheets and flat liner sheets united with each other coincident with the crowns of the corrugations, and marginal multi-ply rabbets formed on opposite sides of said plaster board assembly at lthe opposite edges thereof, for overlapping engagement with multi-ply rabbeted margins of contiguous similar corrugated plaster base assemblies.

16. A corrugated plaster base assembly including superposed strata each comprising corrugated sheets and flat liner sheets united with each other coincident with the crowns of the corrugations, and marginal rabbets at the opposite edges thereof for overlapping engagement with marginal rabbets of different width upon adjacent assemblies, whereby channel spaces will be aorded coincident with the overlapped joints between succeeding assemblies.

17. For use in a plaster base assembly, a laminated sheet including double plies of moisture absorbent material in closely adjacent parallel relation and an interposed stratum of moisture resistant material coextensive therewith and uniting the plies one to the other.

18. For use in a plaster base assembly, a corrugated sheet of material to receive a deposit of moist plaster material including multiple a-dherent plies of sheet material conformingthroughout one to another, having a moisture absorbent face to which the plaster is applied, and a stratum of moisture resistant sealing material interposed between contiguous plies, confining the absorbed moisture to the absorbent face of the sheet and preventing its penetration entirely through the sheet.

. 19. As an article of manufacture, a corrugated paper board including superposed corrugated sheets having therebetween an interposed stratum of waterproof material for preventing the penetration of moisture beyond the exterior corrugated facing sheet and a backing liner sheet to which the corrugated sheets are attached, the exterior face of said backing liner sheet being waterproofed.

JAMES REID. 

